title: Variability in intravenous immunoglobulin G regimens for autoimmune neuromuscular disorders.
abstract: OBJECTIVE
  We reviewed the intravenous immunoglobulin G (IVIG) dispensing records of a specialty pharmacy to characterize the IVIG treatment regimens used for chronic inflammatory demyelinating polyneuropathy (CIDP) and myasthenia gravis (MG) in community practice.
  
  
  METHODS
  Anonymized records were selected based on International Classification of Diseases, Ninth Revision (ICD-9) codes and IVIG treatment for > 1 month. Each patient's immunoglobulin G (IgG) dose per infusion (mg/kg/dose) was multiplied by the number of doses per month (30.5 days divided by the dosing interval in days) to yield the total monthly dose (mg/kg/month). Data were analyzed and summarized using descriptive statistics.
  
  
  RESULTS
  Forty-six patients (median age, 56.5 years; range, 8-86 years) fulfilled the inclusion criteria. Thirty-one patients with CIDP received IgG at 7- to 92-day intervals (mean [standard deviation (SD)], 28 [16] days). The mean (SD) IgG dose was 75 (60) g/dose, equivalent to 866 (623) mg/kg/dose and 1145 (778) mg/kg/month. Six patients with stable MG received IVIG or subcutaneous IgG at 3.5- to 61-day intervals (28 [20] days) at a mean (SD) IgG dose of 39 (15) g/dose, equivalent to 405 (108) mg/kg/dose and 783 (680) mg/kg/month. Nine patients with MG with acute exacerbations received IgG at 7- to 42-day intervals (22 [12] days) at a mean (SD) dose of 40 (21) g/dose, equivalent to 403 (172) mg/kg/dose and 641 (288) mg/kg/month. One patient with CIDP and 4 patients with MG were treated with weekly subcutaneous IgG injections.
  
  
  CONCLUSIONS
  Although patients with CIDP and MG are treated with mean total monthly IgG doses similar to those approved by the US Food and Drug Administration, the individual doses and intervals vary considerably, suggesting that physicians may be adjusting IgG dosing according to each patient's clinical condition and treatment response. Further study is necessary to determine the criteria used to adjust IgG treatment regimens and whether these adjustments optimize clinical outcomes while limiting overall costs.
authors.affiliation: National Director, Operations, BioRx, Cincinnati, OH, USA.
authors.forename: Randy
authors.initials: R
authors.lastname: Broyles
authors.forename: Linda
authors.initials: L
authors.lastname: Rodden
authors.forename: Patty
authors.initials: P
authors.lastname: Riley
authors.forename: Melvin
authors.initials: M
authors.lastname: Berger
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003430:Cross-Sectional Studies; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000008:administration & dosage* / Q000627:therapeutic use; D007155:Immunologic Factors / Q000008:administration & dosage* / Q000627:therapeutic use; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000188:drug therapy*; D020277:Polyradiculoneuropathy, Chronic Inflammatory Demyelinating / Q000188:drug therapy*; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D016756:Immunoglobulins, Intravenous; D007155:Immunologic Factors